Polycyclic polyimides and compositions and methods relating thereto

ABSTRACT

The present invention is directed to the use polycyclic diamines. These diamines, when polymerized with dianhydrides, and optionally other non-polycyclic diamines are used to form new polyamic acids. The polyamic acids can be imidized to form a new class of useful polyimide resins and polyimide films, particularly in electronics type applications.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to polycyclic polyimides,including methods and compositions relating thereto. More specifically,the compositions and methods of the present invention are derived fromcycloaliphatic diamine isomers to provide polycyclic polyimides havingadvantageous properties, particularly as a substitute for glass incertain electronics applications.

2. Background of the Invention

A need exists for a commercially viable glass or quartz substitute fordisplay screens or other similar-type optical communicationapplications. Conventional polyimides are generally not well suited forsuch a use.

U.S. Pat. Nos. 6,710,160; 6,734,276 and 6,812,065 (to Mitsui ChemicalsInc.) describe a diamine mixture of 2,5-NBDA and 2,6-NBDA. However, suchdiamines are not well suited to provide a polyimide having a glasstransition temperature, light transmissability, and coefficient ofthermal expansion (“CTE”), sufficient to be a suitable replacement forquartz or glass in optical display devices or the like.

SUMMARY OF THE INVENTION

Polyimides of the present invention can be represented by the followingformula:

-   -   where R is —CH₃, —CH₂—CH₃, —CH₂—CH₂—CH₃, —(CH₂)₃—CH₃,        —(CH₂)₄—CH₃, —CX₃, —CH₂—CX₃, —CH₂—CH₂—CX₃, —(CH₂)₃—CX₃,        —(CH₂)₄—CX₃ (where X is equal to F, Cl, or Br), —C₆H₅ (a        6-member aromatic ring) and C₆H₅—CH₃ (where the methyl group is        in the ortho or para position on a 6-member aromatic ring),    -   where R₁, is a tetravalent group having from 4 to 27 carbon        atoms and is selected from a group comprising an aliphatic        group, a monocyclic aliphatic group, a condensed polycyclic        aliphatic group, a monocyclic aromatic group, a polycyclic        aromatic group, a substituted aliphatic or aromatic group (e.g.,        fluorine), a condensed aromatic group and/or an non-condensed        polycyclic aliphatic group or an aromatic group in which the        cyclic aliphatic group or aromatic group is connected to each        other directly or via a bridging group, (or mixtures of any of        these),    -   where k is an integer represented by any of the following        numbers, 0, 1, and 2, and    -   where n is an integer ranging between and including any two of        the following numbers, 10, 100, 1000, 10,000 and 100,000.        The present invention also includes polyamic acid precursors to        the above polyimides and also includes processes for converting        such polyamic acids into such polyimides. The polycyclic        polyimides of the present invention can be embodied in a        polyimide resin, a polyimide varnish or coating, and/or a        polyimide film.

The polyimide (or polyamic acid precursor thereto) can be derived fromthe reaction product of a diamine component and dianhydride component,the diamine component can comprise (at least in part) a diamine monomerrepresented by the following general formula (I):

where R is —CH₃, —CH₂—CH₃, —CH₂—CH₂—CH₃, —(CH₂)₃—CH₃, —(CH₂)₄—CH₃, —CX₃,—CH₂—CX₃, —CH₂—CH₂—CX₃, —(CH₂)₃—CX₃, —(CH₂)₄—CX₃ (where X is equal to F,Cl, or Br), —C₆H₅ (a 6-member aromatic ring) and C₆H₅—CH₃ (where themethyl group is in the ortho or para position on a 6-member aromaticring), and where k is an integer and can be equal to 0, 1 or 2.

In one embodiment, the diamine component comprises (at least in part) adiamine monomer represented by the general formula (II) below,

In these diamines however, the —CH₃ group (i.e., the lone pendant methylgroup) is connected to at least one of the carbon atoms that is attachedto at least one of the —CH₂NH₂ groups shown. For these diamines, k is aninteger and can be equal to 0, 1 or 2.

The diamine of formula (I) above is present in the polyimides of thepresent invention either alone (i.e., as the sole diamine of the totaldiamine component) or in combination with other diamines (provided thatthe diamine is present in sufficiently high enough quantities to show anadvantageous property). In addition, the diamine above can be found (andis typically used) to have a variety of different isomers and structuralconfigurations. For example, the diamine of formula (I) can have anorientation where the

—CH₂NH₂ groups and the R group to the norbornane scaffold can vary inposition. In these diamines however, the R group is connected to atleast one of the carbon atoms that is attached to at least one of the—CH₂NH₂ groups shown.

In one embodiment of the present invention, the diamine (—CH₂—) bridgingof the k repeat unit (i.e., when k is equal to 1 or 2) may be on thesame side or may be on the opposite side with respect to the otherbridging —CH₂— group(s).

In another embodiment of this invention, the polycyclic polyimide isprepared by a process comprising the combining of the diamine of formula(I) with a tetracarboxylic dianhydride. The reaction product of thisdiamine with one or more dianhydrides is believed to be represented, atleast approximately or in part, by general formula (III) below,

where R₁ can be any C₄ to C₂₇ carbon structure selected from a groupcomprising an aliphatic group, a monocyclic aliphatic group, a condensedpolycyclic aliphatic group, a monocyclic aromatic group, a polycyclicaromatic group, a substituted aliphatic or aromatic group (e.g.,fluorine), a condensed aromatic group and/or an non-condensed polycyclicaliphatic group or an aromatic group in which the cyclic aliphatic groupor aromatic group is connected to each other directly or via a bridginggroup (or mixtures of any of these) and where n is an integer rangingbetween any two of the following numbers, 10, 100, 1000, 10,000 and100,000.

In the polyimides (and polyamic precursor materials) of the presentinvention, the diamine of formula (II) can generally exist in at least 8different isomeric structures (shown here if k is equal to 0, but alsodisclosed herein if k equals 1 or 2). These isomeric structures can berepresented by at least the following formulas:

In yet another embodiment, a polycyclic polyimide of the presentinvention is created by a process, comprising the steps of combining thediamine of formula (I), with one or more tetracarboxylic dianhydrides,optionally with another diamine represented by the following:NH₂—X—NH₂  (IV)where X can represent a divalent cycloaliphatic group, a divalentaliphatic group (except the divalent group described in formula (I)), adivalent aromatic group, a substituted aliphatic or aromatic group(e.g., fluorine) or a divalent siloxane containing group.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

In one embodiment, the present invention is directed to polyimides, andpolyamic acid solutions, derived from a diamine represented by formula(I) below,

where R is —CH₃, —CH₂—CH₃, —CH₂—CH₂—CH₃, —(CH₂)₃—CH₃, —(CH₂)₄—CH₃, —CX₃,—CH₂—CX₃, —CH₂—CH₂—CX₃, —(CH₂)₃—CX₃, —(CH₂)₄—CX₃ (where X is equal to F,Cl, or Br), —C₆H₅ (a 6-member aromatic ring) and C₆H₅—CH₃ (where themethyl group is in the ortho or para position on a 6-member aromaticring), and where k is an integer and can be equal to 0, 1 or 2.

Diamines useful in accordance with the present invention include diaminemonomers represented by the general formula (II) below,

In these diamines, the —CH₃ group (i.e., the lone pendant methyl group)is connected to at least one of the carbon atoms that is attached to atleast one of the —CH₂NH₂ groups shown. For these diamines, k is aninteger and can be equal to 0, 1 or 2.

The diamine of formula (I) can be polymerized with a dianhydridecomponent to form a polyamic acid and can be thermally cured, via apolycondensation reaction, to form a polyimide represented by formula(III) below,

where R₁ can be any C4 to C₂₇ carbon structure selected from a groupcomprising an aliphatic group, a monocyclic aliphatic group, a condensedpolycyclic aliphatic group, a monocyclic aromatic group, a polycyclicaromatic group, a substituted aliphatic or aromatic group (e.g.,fluorine substituted), a condensed aromatic group and/or annon-condensed polycyclic aliphatic group or an aromatic group in whichthe cyclic aliphatic group or aromatic group is connected to each otherdirectly or via a bridging group (or mixtures of any of these), andwhere n is an integer ranging between (and including) any two of thefollowing numbers, 10, 100, 1000, 10,000 and 100,000.

One example of the diamine of formula (I) can also be expressed (morespecifically) by the following formula (IV) below,

In formula (IV) above, the diamine (under IUPAC nomenclature rules) canbe described as[5-(aminomethyl)-5-methylbicyclo[2.2.1]heptan-2-yl]methylamine.

Another example of the diamine of formula (I) can also be expressed bythe following formula (V) below,

In formula (V) above, the diamine (under IUPAC nomenclature rules) canbe expressed as[6-(aminomethyl)-6-methylbicyclo[2.2.1]heptan-2-yl]methylamine.

In some instances, when one example of the diamine of formula (I) issynthesized or manufactured, the diamine product produced from thatsynthesis (or from that manufacture) is a combination of[5-(aminomethyl)-5-methylbicyclo[2.2.1]heptan-2-yl]methylamine and[6-(aminomethyl)-6-methylbicyclo[2.2.1]heptan-2-yl]methylamine. As such,this combination of diamines (represented as a combination of thediamines represented by formulas (IV) and (V)) can be called, forpurposes of the present invention, 2,5-(or6)-bis(aminomethyl)-2-methyl-bicyclo[2.2.1]heptane.

In the polyimides (and polyamic precursor materials) of the presentinvention, the diamine of formula (II) can exist in at least 8 differentisomeric structures (shown here if k is equal to 0, but also disclosedherein if k equals 1 or 2). These isomeric structures can be representedby the following formulas,

In one embodiment of the present invention, a polyimide is formed usinga diamine in accordance with formula (I) in combination with one or moreother diamines represented by the following:NH₂—X—NH₂  (IV)where X can represent a divalent cycloaliphatic group, a divalentaliphatic group (except the divalent group described in formula (I)), adivalent aromatic group, a substituted aliphatic or aromatic group(e.g., fluorine) or a divalent siloxane containing group in combinationwith a tetracarboxylic dianhydride. The substituted diamine can bepresent in the diamine component in an amount ranging between andincluding any two of the following numbers, 2, 3, 4, 5, 10, 15, 20, 25,30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 and 99 molepercent of the total diamine component. In one embodiment of the presentinvention, the diamine of formula (I) is used in an amount ranging from3 to 50 mole % of the total diamine component.

Useful diamines include, but are not limited to,

-   -   1. trans-1,4-diaminocyclohexane;    -   2. diaminocyclooctane;    -   3. tetramethylenediamine;    -   4. hexamethylenediamine;    -   5. octamethylenediamine;    -   6. nonamethylenediamine;    -   7. decamethylenediamine;    -   8. dodecamethylenediamine;    -   9. aminomethylcyclooctylmethanamine;    -   10. aminomethylcyclododecylmethanamine;    -   11. aminomethylcyclohexylmethanamine;    -   12. 4,4′-diaminodiphenyl methane;    -   13. 4,4′-diaminodiphenyl sulfide (4,4′-DDS);    -   14. 3,3′-diaminodiphenyl sulfone (3,3′-DDS);    -   15. 4,4′-diaminodiphenyl sulfone;    -   16. 4,4′-diaminodiphenyl ether (4,4′-ODA);    -   17. 3,4′-diaminodiphenyl ether (3,4′-ODA);    -   18. 1,3-bis-(4-aminophenoxy)benzene (APB-134);    -   19. 1,3-bis-(3-aminophenoxy)benzene (APB-133);    -   20. 1,2-bis-(4-aminophenoxy)benzene;    -   21. 1,2-bis-(3-aminophenoxy)benzene;    -   22. 1,4-bis-(4-aminophenoxy)benzene (APB-144);    -   23. 1,4-bis-(3-aminophenoxy)benzene;    -   24. 1,5-diaminonaphthalene;    -   25. 1,8-diaminonaphthalene;    -   26. 2,2′-bis(trifluoromethyl)benzidine (TFMB);    -   27. 4,4′-diaminodiphenyldiethylsilane;    -   28. 4,4′-diaminodiphenylsilane;    -   29. 4,4′-diaminodiphenyl-N-methyl amine;    -   30. 4,4′-diaminodiphenyl-N-phenyl amine;    -   31. 1,2-diaminobenzene (OPD);    -   32. 1,3-diaminobenzene (MPD);    -   33. 1,4-diaminobenzene (PPD);    -   34. 2,5-dimethyl-1,4-diaminobenzene;    -   35. 2-(trifluoromethyl)-1,4-phenylenediamine;    -   36. 5-(trifluoromethyl)-1,3-phenylenediamine;    -   37. 2,2-Bis[4-(4-aminopnenoxy)phenyl]-hexafluoropropane;    -   38. 2,2-bis(3-aminophenyl)1,1,1,3,3,3-hexafluoropropane;    -   39. benzidine;    -   40. 4,4′-diaminobenzophenone;    -   41. 3,4′-diaminobenzophenone;    -   42. 3,3′-diaminobenzophenone;    -   43. m-xylylene diamine;    -   44. bisaminophenoxyphenylsulfone;    -   45. 4,4′-isopropylidenedianiline;    -   46. N,N-bis-(4-aminophenyl)methylamine;    -   47. N,N-bis-(4-aminophenyl)aniline    -   48. 3,3′-dimethyl-4,4′-diaminobiphenyl;    -   49. 4-aminophenyl-3-aminobenzoate;    -   50. 2,4-diaminotoluene;    -   51. 2,5-diaminotoluene;    -   52. 2,6-diaminotoluene;    -   53. 2,4-diamine-5-chlorotoluene;    -   54. 2,4-diamine-6-chlorotoluene;    -   55. 4-chloro-1,2-phenylenediamine;    -   56. 4-chloro-1,3-phenylenediamine;    -   57. 2,4-bis-(beta-amino-t-butyl)toluene;    -   58. bis-(p-beta-amino-t-butyl phenyl)ether;    -   59. p-bis-2-(2-methyl-4-aminopentyl)benzene;    -   60. 1-(4-aminophenoxy)-3-(3-aminophenoxy)benzene;    -   61. 1-(4-aminophenoxy)-4-(3-aminophenoxy)benzene;    -   62. 2,2-bis-[4-(4-aminophenoxy)phenyl]propane (BAPP);    -   63. bis-[4-(4-aminophenoxy)phenyl]sulfone (BAPS);    -   64. 2,2-bis[4-(3-aminophenoxy)phenyl]sulfone (m-BAPS);    -   65. 4,4′-bis-(aminophenoxy)biphenyl (BAPB);    -   66. bis(4-[4-aminophenoxy]phenyl)ether (BAPE);    -   67. 2,2′-bis-(4-aminophenyl)-hexafluoropropane (6F diamine);    -   68. 2,2′-bis-(4-phenoxy aniline)isopropylidene;    -   69. 2,4,6-trimethyl-1,3-diaminobenzene;    -   70. 4,4′-diamino-2,2′-trifluoromethyl diphenyloxide;    -   71. 3,3′-diamino-5,5′-trifluoromethyl diphenyloxide;    -   72. 4,4′-trifluoromethyl-2,2′-diaminobiphenyl;    -   73. 4,4′-oxy-bis-[(2-trifluoromethyl)benzene amine];    -   74. 4,4′-oxy-bis-[(3-trifluoromethyl)benzene amine];    -   75. 4,4′-thio-bis-[(2-trifluoromethyl)benzene-amine];    -   76. 4,4′-thiobis-[(3-trifluoromethyl)benzene amine];    -   77. 4,4′-sulfoxyl-bis-[(2-trifluoromethyl)benzene amine;    -   78. 4,4′-sulfoxyl-bis-[(3-trifluoromethyl)benzene amine];    -   79. 4,4′-keto-bis-[(2-trifluoromethyl)benzene amine];    -   80. 9,9-bis(4-aminophenyl)fluorene;    -   81. 1,3-diamino-2,4,5,6-tetrafluorobenzene;    -   82. 3,3′-bis(trifluoromethyl)benzidine;    -   83. 4,4′-diaminobenzanilide,    -   84. o-tolidine sulfone;    -   85. o-tolidine disulfonic acid;    -   86. 4,4′-diamino-3,3′-dicarboxy-diphenyl methane];    -   87. 9,9-bis(4-aminophenyl)fluorene;    -   88. 1,3-bis(4-aminophenoxy)-2,2dimethylpropane;    -   89. diaminodurene;    -   90. 3,3′,5,5′-tetramethylbenzidine;    -   91. a, w-bis(4-aminophenoxy)alkane;    -   92. 1,3-diamino-2,4,5,6-tetrafluorobenzene;    -   93. and the like.

Other possible diamines include divalent cycloaliphatic diamines,divalent aliphatic/aromatic diamines and divalent aromatic diaminescomprising a siloxane group (e.g., diaminosiloxanes). As used herein,polysiloxane diamine is intended to mean a diamine having at least onepolysiloxane moiety (e.g., shown in brackets in the formula below). Forexample, a useful polysiloxane diamine can have the general formula:NH₂—R₁—O—[SiR′R″—O—]_(m)—R₁—NH₂where R′ and R″ are —(CH₃) or —(C₆H₅), where R₁ is —(CH₂)—_(n) and wheren is equal to about 1 to 10 (preferably about 3), and where m is 1 to 40but can be 1 to 12, or can be 8-10. One common diaminosiloxane is3,3′-(1,1,3,3,5,5-hexamethyl-1,5-trisiloxanediyl)-bis-1-propanamine.

A tetracarboxylic dianhydride can be used for the preparation of thepolyimides (and polyamic acid precursors) of the present invention.These dianhydrides can generally be selected from a vast array ofmaterials including cycloaliphatic tetracarboxylic dianhydrides,aliphatic tetracarboxylic dianhydrides, and/or aromatic tetracarboxylicdianhydrides. These dianhydrides may also be used in derivative formssuch as diacid-diesters, diacid halide esters, and tetracarboxylicacids. In one instance, the use of aliphatic tetracarboxylicdianhydrides generally results in the formation of polyimides withexcellent optical characteristics including transparency often thoughgiving up thermal stability. Aromatic tetracarboxylic dianhydridestypically generate polyimides with excellent thermal characteristicssuch as heat resistance and thermal stability. Generally, the diaminesof the present invention, used with traditional aromatic tetracarboxylicdianhydrides, can allow one to produce a polyimide showing improvedthermal stability properties in conjunction with improved opticaltransparency making these polyimides useful in electronic deviceapplications.

Examples of useful dianhydrides of the present invention include

-   -   1. pyromellitic dianhydride (PMDA);    -   2. 3,3′,4,4′-biphenyl tetracarboxylic dianhydride (BPDA);    -   3. 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA);    -   4. 4,4′-oxydiphthalic anhydride (ODPA);    -   5. 3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride (DSDA);    -   6. 4,4′-(4,4′-isopropylidenediphenoxy)bis(phthalic        anhydride)(BPADA);    -   7. 2,3,6,7-naphthalene tetracarboxylic dianhydride;    -   8. 1,2,5,6-naphthalene tetracarboxylic dianhydride;    -   9. 1,4,5,8-naphthalene tetracarboxylic dianhydride;    -   10. 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride;    -   11. 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride;    -   12. 2,3,3′,4′-biphenyl tetracarboxylic dianhydride;    -   13. 2,2′,3,3′-biphenyl tetracarboxylic dianhydride;    -   14. 2,3,3′,4′-benzophenone tetracarboxylic dianhydride;    -   15. 2,2′,3,3′-benzophenone tetracarboxylic dianhydride;    -   16. 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride;    -   17. 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride;    -   18. 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride;    -   19. bis(2,3-dicarboxyphenyl)methane dianhydride;    -   20. bis(3,4-dicarboxyphenyl)methane dianhydride;    -   21. 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA);    -   22. bis(3,4-dicarboxyphenyl)sulfoxide dianhydride;    -   23. tetrahydrofuran-2,3,4,5-tetracarboxylic dianhydride;    -   24. pyrazine-2,3,5,6-tetracarboxylic dianhydride;    -   25. thiophene-2,3,4,5-tetracarboxylic dianhydride;    -   26. phenanthrene-1,8,9,10-tetracarboxylic dianhydride;    -   27. perylene-3,4,9,10-tetracarboxylic dianhydride;    -   28. bis-1,3-isobenzofurandione;    -   29. bis(3,4-dicarboxyphenyl)thioether dianhydride;    -   30. bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylicdianhydride;    -   31. 2-(3′,4′-dicarboxyphenyl)5,6-dicarboxybenzimidazole        dianhydride;    -   32. 2-(3′,4′-dicarboxyphenyl)5,6-dicarboxybenzoxazole        dianhydride;    -   33. 2-(3′,4′-dicarboxyphenyl)5,6-dicarboxybenzothiazole        dianhydride;    -   34. bis(3,4-dicarboxyphenyl)2,5-oxadiazole 1,3,4-dianhydride;    -   35. bis 2,5-(3′,4′-dicarboxydiphenylether)1,3,4-oxadiazole        dianhydride;    -   36. butane-1,2,3,4-tetracarboxylic dianhydride;    -   37. pentane-1,2,4,5-tetracarboxylic dianhydride;    -   38. cyclo butane tetracarboxylic dianhydride;    -   39. cyclo pentane-1,2,3,4-tetracarboxylic dianhydride;    -   40. cyclohexane-1,2,4,5 tetracarboxylic dianhydride;    -   41. cyclohexane-2,3,5,6-tetracarboxylic dianhydride;    -   42. 3-ethyl cyclohexane-3-(1,2)5,6-tetracarboxylic dianhydride;    -   43. 1-methyl-3-ethyl cyclohexane-3-(1,2)5,6-tetracarboxylic        dianhydride;    -   44. 1-ethyl cyclohexane-1-(1,2),3,4-tetracarboxylic dianhydride;    -   45. 1-propylcyclohexane-1-(2,3),3,4-tetracarboxylic dianhydride;    -   46. 1,3-dipropylcyclohexane-1-(2,3),3-(2,3)-tetracarboxylic        dianhydride;    -   47. dicyclohexyl-3,4,3′,4′-tetracarboxylic dianhydride;    -   48. 4,4′-bisphenol A dianhydride;    -   49. 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride;        (−)-[1S*,5R*,6S*]-3-oxabicyclo[3.2.1]octane-2,4-dione-6-spiro-3-(tetrahydrofuran-2,5-dione)        [i.e., (−)-DAN, manufactured by JSR Corp.];    -   50. bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylicdianhydride;    -   51. hydroquinonediphthalic anhydride;    -   52. ethyleneglycol bis(trimellitic anhydride);    -   53. and the like.

Other useful dianhydrides include 9,9-disubstituted xanthenes. Thesedianhydrides include, but are not limited to,9,9-bis-(trifluoromethyl)xanthenetetracarboxylic dianhydride (6FCDA);9-phenyl-9-(trifluoromethyl)xanthenetetracarboxylic dianhydride (3FCDA);9,9-diphenyl-2,3,6,7-xanthenetetracarboxylic dianhydride (PPXDA);9,9-diphenyl-2,3,6,7-tetramethylxanthene (TMPPX);9,9-diphenyl-2,3,6,7-xanthenetetracarboxylic Bis(p-anisidylimide);9,9-diphenyl-2,3,6,7-xanthenetetracarboxylic Bis(butylimide);9,9-diphenyl-2,3,6,7-xanthenetetracarboxylic Bis(p-tolylimide);9-phenyl-9-methyl-2,3,6,7-xanthenetetracarboxylic dianhydride (MPXDA);9-phenyl-9-methyl-2,3,6,7-xanthenetetracarboxylic Bis(propylimide);9-phenyl-9-methyl-2,3,6,7-xanthenetetracarboxylic Bis(p-tolyimide);9,9-dimethyl-2,3,6,7-xanthenetetracarboxylic dianhydride (MMXDA);9,9-dimethyl-2,3,6,7-xanthenetetracarboxylic Bis(propylimide);9,9-dimethyl-2,3,6,7-xanthenetetracarboxylic Bis(tolylimide);9-ethyl-9-methyl-2,3,6,7-xanthenetetracarboxlylic dianhydride (EMXDA););9,9-diethyl-2,3,6,7-xanthenetetracarboxylic dianhydride (EEXDA); etc.(as disclosed in Polyimides Based on 9,9-Disubstituted XantheneDianhydrides, Trofimenko and Auman, Macromolecules, 1994, vol. 27, p.1136-1146, herein incorporated by reference).

The tetracarboxylic dianhydrides mentioned above can be usedindependently, depending on the purpose of the use, or can be used asmixture of two or more individual dianhydrides. Many of the abovementioned dianhydrides (if not all) can also be used in their‘tetra-acid form’ (or as mono, di, tri, or tetra esters of the tetraacid), or as their diester acid halides (chlorides). In some embodimentsof the present invention however, the dianhydride form is generallypreferred because it is generally more reactive than the acid or theester.

The polyimides of this invention, and their polyamic acid precursors,can be prepared using a polar organic solvent such as a phenolic solventsystem or aprotic polar solvent system. For example, solvents or solventmixtures based on phenol, phenol, 4-methoxy phenol, 2,6-dimethyl phenol,m-cresol (etc.) can be used. Alternatively aprotic solvents can also beused alone (or in combination with protic solvents). Some usefulsolvents include, but are not limited to, N-methylpyrrolidone (it ishereafter written as NMP), N,N-dimethylformamide (it is hereafterwritten as DMF), N,N-dimethylacetamide (it is hereafter written asDMAc), dimethyl sulfoxide (it is hereafter written as DMSO),gamma-butyrolactone, gamma-valerolactone and n-cyclohexyl pyrrolidone.Other useful solvents include, but are not limited, to chloroform,tetrahydrofuran (it is hereafter written as THF), cyclohexanone,dioxane, anisole, 2-methoxy ethanol, propylene glycol methyl ether,propylene glycol methyl ether acetate, “Cellosolve™” (ethylene glycolethyl ether), butyl “Cellosolve™” (ethylene glycol butyl ether),“Cellosolve™ acetate” (ethylene glycol ethyl ether acetate), and “butylCellosolve™ acetate” (ethylene glycol butyl ether acetate), propyleneglycol, monoethylether acetate, methylmethoxypropionate, lactic acidethyl ester, and the like. The above described reaction solvents can beused independently or as mixtures.

Alternatively, the solvent systems described above can also be used incombination with aromatic hydrocarbon solvents, for example benzene,toluene xylene, or tetralin (these solvents being useful towards theremoval of water generated during the imide conversion process). Themanufacturing process for the polyimide resin starting from a diamineand a tetracarboxylic dianhydride may be carried out by well-known,conventional one-step polymerization methods in which the polymerizationis carried out at high temperatures using an almost equal amount (inmoles) of diamine and tetracarboxylic dianhydride. When using a one-steppolymerization method, the preferred reaction temperature can be in therange of 120-350° C. or from about 150-300° C. Possible reaction timesin a one step process can be from about 0.5 to 20 hours or from about 1to 15 hours.

The making of the polyimide resins of the present invention can also bestarted by a two-step polymerization method. In the first step, apolyamic acid is synthesized at a low temperature. In the second step,the polyamic acid is converted to a polyimide at a higher temperature.When using a two-step polymerization method, the polyamic acid synthesiscan be carried out at about −10° to 120° C. (or from about 15° to 100°C., or 20° to 80° C.) and the reaction time can be about from about 0.5to 100 hours (or from about 1-100 hours). After which, the conversion ofthe polyamic acid to a polyimide can be carried out at a temperature offrom about 120°-350° C. (or about 150°-300° C.) wherein the reactiontime is about 0.5-20 hours (or about 1-10 hours).

If two or more different diamines (or different tetracarboxylicdianhydrides) are used, the polymer reaction method is typically notlimited (i.e., various reaction methods may be utilized for theprocess). For example, one reaction method can be used to conduct thepolymerization after mixing of all the starting materials, and such amethod is particularly useful if a random polyimide resin is desired. Inan alternative reaction method, two or more diamines or tetracarboxylicdianhydrides are added sequentially, where the monomers are added to thereaction vessel in a controlled fashion, and this method can be usefulfor preparing block or segmented polyimide resins.

In another embodiment if the polyimide backbone is soluble, a solublepolyimide resin solution can be obtained and can be used to form asoluble polyimide resin by removal of the solvent. A purified solublepolyimide resin can be obtained by using a precipitation method in whicha poor solvent is used to precipitate the above-mentioned polyimidesfrom the polyimide resin solution. This polyimide resin can be furtherpurified and can later be used as a soluble polyimide after againdissolving the polyimide solution into an appropriate organic solvent(or mixture on having the desired polarity.

The polyimides of the present invention may be prepared using a varietyof different methods with respect to how the components (i.e., themonomers and solvents) are introduced to one another. Numerousvariations of producing a polyamic acid solution include:

-   -   (a) a method wherein the diamine components and dianhydride        components are preliminarily mixed together and then the mixture        is added in portions to a solvent while stirring.    -   (b) a method wherein a solvent is added to a stirring mixture of        diamine and dianhydride components (contrary to (a) above).    -   (c) a method wherein diamines are exclusively dissolved in a        solvent and then dianhydrides are added thereto at such a ratio        as allowing to control the reaction rate.    -   (d) a method wherein the dianhydride components are exclusively        dissolved in a solvent and then amine components are added        thereto at such a ratio to allow control of the reaction rate.    -   (e) a method wherein the diamine components and the dianhydride        components are separately dissolved in solvents and then these        solutions are mixed in a reactor.    -   (f) a method wherein the polyamic acid with excessive amine        component and another polyamic acid with excessive dianhydride        component are preliminarily formed and then reacted with each        other in a reactor, particularly in such a way as to create a        non-random or block copolymer.    -   (g) a method wherein a specific portion of the amine components        and the dianhydride components are first reacted and then the        residual diamine components are reacted, or vice versa.    -   (h) a method wherein the components are added in part or in        whole in any order to either part or whole of the solvent, also        where part or all of any component can be added as a solution in        part or all of the solvent.    -   (i) a method of first reacting one of the dianhydride components        with one of the diamine components giving a first polyamic acid.        Then reacting the other dianhydride component with the other        amine component to give a second polyamic acid. Then combining        the amic acids in any one of a number of ways prior to film        formation.

Generally speaking, a polyamic acid casting solution can be derived fromany one of the polyamic acid solution preparation methods disclosedabove.

The polyamic acid casting solutions of the present invention comprisesboth a polyamic acid solution combined with some amount of conversionchemicals. The conversion chemicals found to be useful in the presentinvention include, but are not limited to, (i) one or more dehydratingagents, such as, aliphatic acid anhydrides (acetic anhydride, etc.) andaromatic acid anhydrides; and (ii) one or more catalysts, such as,aliphatic tertiary amines (triethylamine, etc.), aromatic tertiaryamines (dimethylaniline, etc.) and heterocyclic tertiary amines(pyridine, picoline, isoquinoilne, etc.). The anhydride dehydratingmaterial is typically used in a slight molar excess of the amount ofamide acid groups present in the polyamic acid solution. The amount ofacetic anhydride used is typically about 2.0-3.0 moles per equivalent ofthe polyamic acid. Generally, a comparable amount of tertiary aminecatalyst is used. Alternatively, a thermal conversion process can beused, i.e., a process that employs only heat to cure the polyimide fromits polyamic acid precursor state.

During the conversion to a polyimide, water is typically generated dueto the ‘ring-closure’ of the polyamic acid precursor material. The watermay be removed during the process to promote further conversion of theacid to the imide. Water removal may be accomplished by azeotropicdistillation with benzene, toluene, xylene, tetralin, or other suitableagent with the objective of removing the water from the reaction system.Alternatively, a dehydration agent may be utilized (such as anhydrousacetic acid or molecular sieves) to accelerate the conversion rate ofthe polyamic acid to a polyimide. Optionally, an imidization catalystmay be added to the reaction mixture. Typical basic imidization catalystuseful in the present invention include for example,N,N-dimethylaniline, N,N-diethylaniline, pyridine, quinoline,isoquinoline, α-picoline, β-picoline, γ-picoline, 2,4-lutidine,triethylamine, tributylamine, tripentylamine, N-methylmorpholine, etc.Other typical imidization include benzoic acid, o-hydroxybenzoic acid,m-hydroxybenzoic acid, p-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid,p-hydroxyphenyl acetic acid, 4-hydroxyphenylpropylene acid, phosphoricacid, p-phenol sulfone acid, p-toluene sulfone acid, crotonic acid etc.The loading level of the above-described imidization catalysts should bein the range of 1-50 mol %, or 5-35 mol %, with respect to the diamineor the mixture of diamines. Using these condensation polymerizationcatalysts, the polymerization reaction may be carried out at a lowertemperature. This protocol might be of advantage if coloration isavoided and if the reaction time is reduced in the process.

In one embodiment of the present invention a polyimide film is formedhaving a thickness of between (and including) any two of the followingnumbers, 2, 5, 10, 15, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, 100, 150,200, 250 and 300 microns. Typically, the polyimides of the presentinvention can have a glass transition temperature of about 250° C.,especially when derived from BPDA as the dianhydride component. In manycases the polyimides of the present invention have a glass transitiontemperature between any two of the following numbers, 200, 220, 240,260, 280, 300, 320 and 360° C.

In one embodiment of the present invention, a polyimide is formed havinga glass transition temperature between and including any two of thefollowing numbers, 550, 530, 510, 490, 470, 450, 430, 410, 390, 370,350, 330, 310, 290, 270, 250, 220, 200, 150 and 100° C.

In one embodiment of the present invention, fillers can be added to thepolyimide formulation to form a polyimide composite. Some fillersinclude, but are not limited to, aluminum oxide, silica, boron nitride,boron nitride coated aluminum oxide, granular alumina, granular silica,fumed silica, silicon carbide, aluminum nitride, aluminum oxide coatedaluminum nitride, titanium dioxide, dicalcium phosphate, bariumtitanate, barium strontium titanate (BST), lead zirconate titanate(PZT), lead lanthanum titanate, lead lanthanum zirconate titanate(PLZT), lead magnesium niobate (PMN), and calcium copper titanate,carbon powder and titanium dioxide, indium oxide, tin oxide, zinc oxide,cadmium oxide, gallium oxide silicon carbide, diamond, dicalciumphosphate, polyaniline, polythiophene, polypyrrole,polyphenylenevinylene, polydialkylfluorenes, and electrically conductivepolymers and combinations thereof. In one embodiment, nano-sized fillerin accordance with the present invention (i.e., alumina oxide particles)are first dispersed in a solvent to form a slurry. The slurry is thendispersed in the polyamic acid precursor solution. This mixture isreferred to herein as a filled polyamic acid casting solution. Theconcentration of filler to polyimide (in the final composite film) istypically in the range of 40, 45, 50, 55, 60, 65, 70, 75, 80 or 85(%)percent by weight. As the concentration of the filler increases, thethermal conductivity of the composite polyimide also increases. Here afiller can be present in a concentration range from about 1, 3, 5, 7, 9or 10 weight (%) percent to about 15, 20, 25, 30, 35, 40, 45 or 50(%)weight percent or greater and can generally have an average particlesize (in the polyimide binder matrix) in a range between and includingany two of the following sizes: 100, 125, 150, 175, 200, 250, 300, 350,400, 450, 500, 1000, 2000, 3000, 4000, and 5000 nanometers, where atleast 80, 85, 90, 92, 94, 95, 96, 98, 99 or 100 weight-percent of thedispersed filler is within the above defined size range(s)

It would be impossible to discuss or describe all possiblepolyimide-metal laminate manufacturing processes useful in the practiceof the present invention. It should be appreciated that the monomersystems of the present invention are capable of providing theabove-described advantageous properties in a variety of manufacturingprocesses. The compositions of the present invention can be manufacturedas described herein and can be readily manufactured in any one of many(perhaps countless) ways of those of ordinarily skilled in the art,using any conventional or non-conventional polyimide (and multi-layer)manufacturing technology.

A conductive layer (typically a metal) can be formed on the polyimidesof the present invention by:

-   -   i. metal sputtering (optionally, then electroplating);    -   ii. foil lamination; and/or    -   iii. any conventional or non-conventional method for applying a        thin metallic layer to a substrate.

A conductive layer as used herein can be a metal selected from the groupconsisting of copper, steel (including stainless steel), aluminum,brass, a copper alloy, a metal alloy derived from copper and molybdenum,Kovar®, Invar®, a bimetal, a trimetal, a trimetal derived fromtwo-layers of copper and one layer of Invar®, and a trimetal derivedfrom two layers of copper and one layer of molybdenum.

In one embodiment of the present invention, the high T_(g) polyimidelayer is placed between a conductive layer. Optionally, a low T_(g)polyimide layer can be used to bond together the metal and the high Tglayer. The high Tg layer is typically used to improve structuralintegrity and/or improved stability of the laminate to environmentalchanges, such as heat and humidity. An electronic circuit (defined by,connected to, or otherwise integrated with the metal layer) can showimproved low (signal) loss in high-speed digital applications.

In another embodiment of the present invention, a low T_(g) polyimidelayer is placed between a conductive layer and a high T_(g) polyimidelayer, and a second low T_(g) polyimide layer is placed on the oppositeside of the high T_(g) polyimide. One advantage of this type ofconstruction is that the lamination temperature of the multi-layersubstrate is lowered to the lamination temperature necessary for the lowT_(g) polyimide layer to bond. In one embodiment, the low Tg and high Tglayers are cast simultaneously as one polyamic acid film and then curedto form a three-layer polyimide. In yet another embodiment, a high Tglayer is bonded to a metal using an adhesive made from an epoxy,cyanate, urethane, melamine, acrylic, phenolic, phenolic butyral, imideor a combination thereof.

In one embodiment of the present invention, the polyimides disclosedherein can be used to form a polyimide fiber. In addition, thepolyimides herein can be used to form a molded part. These polyimidescan be extruded to form gaskets, rings, diaphragms, mechanical parts andcomponents, wire coatings, and the like.

In one embodiment of the present invention a polyimide is formed havingthe formula represented below;

The polyimide shown in formula (VI) is typically formed from a mixtureof isomeric diamines based on the mixtures (and isomers) describedabove. Another common polyimide of the present invention can be shown bythe following formula below,

The polyimide films of the present invention can show excellent lighttransparency as well as high Tg. These two properties together can allowthe polyimide film to be useful in making a flexible substrate materialin an organic light emitting diode (OLED) display or a liquid crystaldisplay (LCD). These polyimides can also be useful in other electronicapplications such as a coating material for electronic parts (such asIC's). Other useful applications include, but are not limited tooptoelectronic materials (such as liquid crystal-based membranes), colorfilter blanket films, electronic switches for optical response systems,integrated circuit chip stress buffers, interlayer dielectrics, or as amaterial for an optical fiber.

In another embodiment of the present invention, when the diamines offormula (I) are used in combination with other diamines disclosed in ageneral list, other physical properties of the polyimide can beimproved. One physical property in particular important to manyapplications is adhesion. This property can be improved especially whenthe diamine substitute in is a diaminosiloxane. The polyimides of thepresent invention, derived in part from diaminosiloxane, can bedissolved in low boiling point solvents such as cyclohexanone, dioxane,and lactic acid ethyl ester. This can allow one to form polyimide filmhaving good adhesion to a silicon wafer (i.e., generally without havingto sacrifice light transparency and thermal stability) as well asmaintaining a relatively low range of processing temperatures.

Although the following examples explain this invention in detail, therange of this invention is not limited by these examples.

EXAMPLES

In the following EXAMPLES, measurements of a variety of physicalproperties were recorded. For glass transitional temperatures, adifferential scanning calorimetry (DSC) method was used using a TAInstruments 2910 DSC. A 5 to 10 mg of sample was placed in thenon-hermetic sample pan. The test was performed under 50 ml/min N₂ flowfrom ambient temperature to 400° C. at 10° C./min rate. For lighttransmittance (T %), the transmittance data was obtained with a Cary 500UV/VIS/NIR spectrometer from Varian. The spectrum of 200 nm to about 700nm was collected under air background. The coefficient of thermalexpansion (CTE) of these samples was analyzed using a thermal mechanicalanalyzer (TMA). The device is capable of reading the dimensional changeof a film sample as it is heated. During the test, the film was held ata constant load of about 0.05 N. The CTE for each film sample wasdetermined by performing a linear regression of the data obtained in thetemperature range of about 50° C. to 250° C. Film thickness at themeasurement point was about 3.3 to about 4.3 mils and calculated on a4.0 mil basis (or about 100 microns).

Example 1

In a 250-ml two-neck flask with N₂ blanket, 38.88 g of pyromelliticdianhydride (PMDA) was dissolved in 120 ml DMAc with mechanicalstirring. Then, 30.0 g of 2,5-(or6)-bis(aminomethyl)-2-methyl-bicyclo[2.2.1]heptane (k=0, i.e. diaminerepresented by structure (I) above, being mixture of formula IV and V)was mixed with 40 ml DMAc and then added into the flask dropwise over 3hrs. while maintain the reaction mixture at about 0° C. The solution wasallowed to polymerize into a viscous polymer.

The reaction mixture was maintained at room temperature overnight.Precipitation was initially observed, but the precipitate graduallydissolved with agitation. The mixture eventually became a clear, viscousliquid.

The reaction mixture was then heated to 35° C. for about 72 hrs. At thistemperature, most if not all of any precipitate was completelydissolved. A portion of the reaction solution was cast on a 5″×7″ glassslides using a 10-mil thick blade. The glass slides, with the polymerfilms, were kept under vacuum and room temperature for about 3 hrs. Fromthese slides, polyimide films were prepared.

Additional polymer reaction mixture was added into acetone. Theresultant precipitated polymer (polyamic acid) was filtered and thendried at room temperature over night under vacuum. A portion of thepolyamic acid was coated onto a 5″×7″ glass slide. From this, apolyimide film was formed by putting the vacuum treated polymer (PAA)film (on a glass slide) into an oven (purged with N₂) at a temperatureprofile of 60° C. (1 hr), 100° C. (1 hr), and 200° C. (1 hrs). DMAC andwater were purged from the oven using a continuous N₂ feed.

After cooling to about 50° C., the polyimide film was taken out of theoven, and then separated from the glass substrate by immersing the glasssubstrate (with film) into boiling water. The separated polyimide filmwas put into a vacuum oven at 300° C. and further cured for about 1 hr.under vacuum. Film properties are shown in Table 1 below.

Example 2

In a 50-ml three-neck flask with N₂ blanket, 9.8 g of pyromelliticdianhydride (PMDA) was dissolved in 35 ml of DMAc using a magneticstirrer. Next, 10.5 g of 2,5 (or6)-bis(aminomethyl)-2-methyl-bicyclo[2.2.1]heptane (i.e. k=1) was addedwith dilution using an additional 10 ml of DMAc. The polymerizationreaction was maintained at 0° C. for about 1 hour. Precipitation wasobserved. The mixture was kept at room temperature overnight.Subsequently, the reaction mixture was kept at 60° C. for about 72 hrs.A portion of reaction solution was cast onto a 5×7-cm glass slide andkept under vacuum, and at room temperature, for about 3 hrs. Thisrelease trapped bubbles.

Next, the cast polymer was converted to a polyimide film. Thetemperature for this conversion was adjusted per the following, 60° C.(1 hr), 100° C. (1 hr), 200° C. (1 hrs). As a result of this conversion,most of the DMAc and water was purged from the film under continuous N₂feed. After cooling of the film (down to about 50° C.), the filmsubstrate was taken out of the oven. The polyimide film was separatedfrom the glass substrate by immersing the glass substrate (and film)into boiling water. The separated polyimide film was put into a vacuumoven, set at 300° C., and further cured for 1 hr. Film properties areshown in Table 1 below.

Example 3

In a 250-ml two-neck flask with N₂ blanket, 43.7 g of3,3′,4,4′-biphenytetracarboxylic dianhydride (BPDA) was dissolved in 120ml DMAc with magnetic stirring. Next, 25.0 g of 2,5-(or6)-bis(aminomethyl)-2-methyl-bicyclo[2.2.1]heptane (i.e., k=0) wasdissolved in 40 ml DMAc and was added into the flask via an additionalfunnel drop by drop over 3 hrs while maintaining the entire flask ˜0° C.A mechanical stirrer was used. After all diamine/DMAc was added, theentire mixture became highly viscous with off-white color. The reactionwas maintained at 30° C. overnight. The large lump was dissolvedovernight and the entire mixture became viscous clear liquid with somelight yellowish color. Little undissolved solid was observed. Then thereaction was kept at 35° C. for 72 hours (or until practically all ofthe precipitate was dissolved). The reaction mixture remainedtransparent and relatively homogeneous having a light yellowish color.

A portion of the reaction solution was cast onto a 5″×7″ glass slideusing a 10-mil blade. The cast polymer was kept under vacuum and at roomtemperature for about 3 hours to remove trapped bubbles.

The cast polyamic acid film was converted to a polyimide film by puttingthe pre-vacuumed polymer into an oven purged with N₂. The temperaturewas set at 60° C. (1 hr), 100° C. (1 hr) and 200° C. (1 hr). Excess DMAcand water were purged from the oven using a continuous feed stream ofN₂.

After cooling to ˜50° C., the film substrate on glass was taken out ofthe oven. The polyimide film was separated from the glass substrate byimmersing the glass (and film) into boiling water. The freed polyimidefilm was put into a vacuum oven at a temperature of 300° C. and curedfor about 1 hour under vacuum. The final polyimide obtained had goodmechanical integrity and had a light yellowish color. Film propertiesare shown in Table 1 below.

Comparative Example 1

In a 250-ml two-neck flask with N2 blanket, 41.44 g of pyromelliticdianhydride (PMDA) was dissolved in 120 ml DMAc with mechanicalstirring. Next, 29.31 g of norbornane diamine (NBDA diamine made byMitsui Chemicals Inc., a mixture of diamines comprising 2,5-NBDA and2,6-NBDA, IUPAC name being 2,5(and6)-Bis(aminomethyl)bicyclo[2.2.1]heptane) was diluted into 40 ml ofDMAC. The diamine solution was then added to the dianhydride solutionvia a funnel drop by drop over 3 hours while maintaining the temperatureat about 0° C.

After all of the diamine solution was added the mixture became viscousand had a pink hue. The polymerization reaction was maintained at roomtemperature overnight. Some precipitation was observed and was allowedto dissolve overnight. The mixture became a viscous, clear liquid havinga yellowish tint. Next, the polymer was aged at 35° C. for 72 hour untilall of the precipitation was dissolved.

A portion of polymer was cast onto a 5″×7″ glass slide using a 10-milblade. The casting was kept under vacuum and at room temperature forabout 3 hours to remove trapped bubbles.

A polyimide film was formed by putting the pre-vacuumed cast polymer (apolyamic acid) into an oven (purged with N2) and set at a temperature ofabout 60° C. (for 1 hr.), at 100° C. (for 1 hr.), and 200° C. (for about1 hour). DMAc and water were purged out of oven using a continuous feedstream of nitrogen.

After cooling down to about 50° C., the substrate was taken out of theoven and was separated from the glass substrate by immersing the glasssubstrate (and the film) into boiling water.

The polyimide film was put into a vacuum oven at 300° C. and thermallycured for 1 hour. The final polyimide obtained had a yellowish color andhad good physical integrity. Film properties are shown in Table 1 below.

TABLE 1 PI FILM EXAMPLE EXAMPLE EXAMPLE COMP. PROPERTY 1 2 3 EX. 1 LightTrans. % 85.4 49.5 84.1 45.0 (400~700 nm) CTE 51.9 58.8 51.9 61.0 (ppm/°C.) Tg (DMA) 355.6° C. 326.1° C. 255.5° C. 324.2° C.

1. A polyimide composition derived from a diamine component and adianhydride component wherein the diamine component comprises from 3 to25 mole percent of a diamine represented by the following formula,

where R is —CH₃, —CH₂—CH₃, —CH₂—CH₂—CH₃, —(CH₂)₃—CH₃, —(CH₂)₄—CH₃, —CX₃,—CH₂—CX₃, —CH₂—CH₂—CX₃, —(CH₂)₃—CX₃, —(CH₂)₄—CX₃ where X is equal to F,Cl, or Br, —C₆H₅ and ortho or para C₆H₅—CH₃ wherein k is either 1 or 2,wherein the diamine component comprises from between 75 and 97 molepercent of a diamine represented by the following formula,NH₂—X₁—NH₂ wherein X₁ stands for a divalent aliphatic group, a divalentaromatic group, or a divalent siloxane containing aliphatic or aromaticgroup, and wherein the dianhydride component is selected from the groupconsisting of a dianhydride, a diacid-diester, a diacid halide ester, ora tetra-carboxylic acid.
 2. A composition in accordance with claim 1wherein the polyimide component has a glass transition temperaturebetween and including 550 and 330° C.